Snap lock assembly

Abstract

 The snap lock assembly (1) has a base member (10), a link member (14), a latch member (16) and an operating member (18) that are pivotally connected to one another to form a four link mechanism. The base member is configured for mounting on the openable aperture closure member, e.g. a window sash and a striking plate is mounted on the frame, e.g. a window sill. The latch member is provided with a protruding member (21) for engaging a striking plate. The axis of a roller (22) on the protruding member is positioned offset relative to the hinge connecting the link member to the latch member so that a large force in the opening direction is less likely to cause the snap lock to be forced open.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to a snap lock assembly for securing an openable aperture closure member in closed position relative to an aperture defined by frame, and in particular to a snap lock assembly with a spring loaded four link mechanism.

BACKGROUND OF THE INVENTION

[0002] EP 727,002 discloses a snap lock assembly and a striking plate. The snap lock assembly has a base member, a link member, a latch member and an operating member that are pivotally connected to one another to form a four-link mechanism. The base member is configured for mounting on the openable aperture closure member, e.g. a window sash and a striking plate is mounted on the frame, e.g. a window sill. The pivotal connection between the operating member and the latch member can be displaced in a slot against a spring by a bias, thereby allowing the latch member to retract and thereafter snap into locking position whilst passing the striking plate when the window is slammed shut. The latch member can be moved against a spring bias from an outer locking position to an inner opening position when an operator manipulates the operating member accordingly.

[0003] This known snap lock assembly has proven to be reliable, user-friendly and a generally very satisfying product.

[0004] However, it has now been realized by the inventors that the capacity of this known snap lock assembly to resist capacity of resisting a large impact force (such as by a heavy object hitting the window with considerable speed), could be improved.

DISCLOSURE OF THE INVENTION

[0005] On this background, it is an object of the present invention to provide a snap lock assembly with an improved capacity to resist forced opening.

[0006] This object is achieved by providing a snap lock assembly for securing an openable aperture closure member in closed position relative to an aperture defined by a frame, said snap lock assembly comprising a base member for mounting on the aperture closure member, a link member, a latch member, and an operating member for manipulation by an operator, said link member is connected to the base member by a first hinge with a first pivot axis, said latch member is connected to said link member by a second hinge with a second pivot axis, said operating member is connected to said latch member by a third hinge with a third pivot axis, said base member is connected to said operating member by a fourth hinge with a fourth pivot axis, so that the base member, the link member, the latch member and the operating member form a four-link mechanism,
said four link mechanism enables the latch member to move between an extended locking position and a retracted opening position, said latch member is provided with a protruding part for engagement with a striking plate, said protruding part provided with a roller for contact with a locking face of the striking plate, said roller having a fifth pivot axis and said base member has a substantially planar abutment face for abutment with a face of the openable aperture closure member, wherein said fifth pivot axis is offset relative to said second pivot axis in the

[0007] direction of the operating member when the latch member is in its closed position.

[0008] By positioning the contact point of the latch member well towards the operating member any tendency of the snap lock to open when an excessive force is applied thereto is reduced.

[0009] Preferably, a straight line perpendicular to said abutment face and intersecting said fifth pivot axis is offset by a substantial distance d in the direction of the operating member from a straight line perpendicular to said abutment face intersecting with the second pivot axis when the latch member is in its closed position.

[0010] The first pivot axis, said second picot axis, said third pivot axis and said fourth pivot axis are mutually parallel and substantially parallel with said abutment face.

[0011] The snap lock assembly may further comprise a striking plate assembly, and wherein the striking plate assembly may further comprise a first plate member for mounting on to the frame member and a second plate member for counter sunk mounting in the frame member.

[0012] The first plate like member of the striking plate assembly and/or said second plate like member of the striking plate assembly can be provided with means to prevent in the first plate member to displace relative to the second plate number.

[0013] The object above can also be achieved by providing a striking plate assembly for engaging a latch member of a snap lock, said striking plate assembly comprises a first plate like member for mounting on a surface of the object to which the striking plate assembly is to be attached and a second plate like member for countersunk mounting in the surface of the object to which the striking plate assemblies to be attached, said first plate like member is provided with a projection on its front face that creates a locking face and two parallel projections on its front face that create sidewalls that in combination with the locking face define a recess in the front face of the first plate like member for receiving portion of the latch member, a slot for receiving a screw or the like but therethrough is formed in said recess and a portion of the rear side of the first plate like member is provided with serrations or the like, and said second plate like member is provided corresponding serrations or the like on its side that faces the first plate like member.

[0014] Preferably, the serrations or the like are substantially parallel to the locking face.

[0015] Further objects, features, advantages and properties of the snap lock and striking plate according to the invention will become apparent from the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the following detailed portion of the present description, the invention will be explained in more detail with reference to the exemplary embodiments shown in the drawings, in which:

Figure 1 is an elevated view of the snap lock assembly according to an embodiment of the invention

Figure 2 is an elevated view of the snap lock assembly of figure 1 in a partially exploded view,

Figure 3 is a top view of the snap lock assembly of figure 1,

Figure 4 is a bottom view of the snap lock assembly of figure 1,

Figure 5 is a side view on the snap lock assembly of figure 1 in an opening position,

Figure 6 is a sectional view through the snap lock assembly of figure 1 in a locking position also showing a striker plate assembly,

Figure 7 is a sectional view through the snap lock assembly of figure 1 in an opening position, also showing a striker plate assembly,

Figure 8 is an elevated view of a striking plate assembly according to an exemplary embodiment of the invention,

Figure 9 is a bottom view of a striking plate assembly of figure 8,

Figure 10 is a side view of the striking plate assembly of figure 8, and

Figure 11 is a side view of the striking plate assembly of figure 8 when it is assembled.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In the following detailed description of the snap lock assembly according to the invention will be described by the exemplary embodiments.

[0018] Figures 1 to 7 show a snap lock assembly 1 according to an exemplary embodiment of the invention in a locking position, and also show an embodiment of a striking plate assembly. Figure 3 shows the snap lock assembly 1 mounted on an openable mounted on an openable aperture closure member, which is in this embodiment the sash 4 of a window. The striking plate assembly 50 is mounted to a frame surrounding the openable aperture, and in this embodiment the frame is a window sill 5. With the window shut and the snap lock 1 engaging the striking plate 50 the sash is firmly pressed against a gasket (not shown).

[0019] The snap lock 1 has a base member 10 that is provided with an abutment face 12 for mounting on a face of the window sash 4.

[0020] The snap lock 1 has a base member 10, a link member 14, a latch member 16, and an operating member 18 that are pivotally connected to one another to form a four-link mechanism. This four-link mechanism allows the latch member to assume the locking position shown in figures 1-4 and 6 and the opening position shown in figures 5 and 7.

[0021] The operating member 18 is surrounded by a cover member 25. The operating member 18 is provided with two projecting ledges 23 is for attachment of a handlebar (not shown) to the operating member 18).

[0022] The latch member 16 is L-shaped whereby the short portion of the L serves as a projection portion 21 on which a roller 20 is mounted for engaging the striking plate 52 of the striker plate assembly. The roller 22 is supported from a pin 20 that is carried by the projection portion 21.

[0023] One end of the link member 14 is pivotally connected to one end of the base member 10 by a hinge including a hinge pin 13 that defines a first pivot axis. The other end of the link member 14 is pivotally connected to the corner of the L-shaped latch member 16 by a second hinge including a hinge pin 15 that defines a second pivot axis. The other end of the long portion of the L-shaped latch member 16 is pivotally connected to the operating member 18 by hinge including a hinge pin 17 that defines a third pivot axis. The other end of the base member 10 is connected to the operating member 18 by a hinge including a hinge pin 19 that defines a fourth pivot axis.

[0024] The first pivot axis, the second pivot axis, the third pivot axis and the fourth pivot axis are mutually parallel.

[0025] The base member 10 is provided with two hollow legs 24 that are received in bores in the window sash 4. A particularly strong connection between the sash 4 and the base member 10 can be achieved by screwing bolts into the hollow and internally threaded legs 24 from the opposite side of the sash 4.

[0026] The operating member 18 is provided with a slot 26 in which the pin 17 of the third hinge is guided. A compression spring 27 urges the pin 17 in engagement with the end of the slot that his most far away from the fourth pivot axis. The operating member 18 is biased to rotate towards the position in which the latch member 16 is in the locking position by means of a helical torsion spring 29.

[0027] When the snap lock according to the invention is used as an ordinary snap lock, e.g. when the window frame is shut, the window sash 4 will pass by the striking plate 52 and so does the link member 14. Hereby, the latch 16 member will be forced over the striking plate 52 against the pressure of the spring 27, so that the hinge pin 17 is forced away from abutment at the extremity of the slot 26. When the roller 22 of the latch member 16 has passed the front edge 54 of the striking plate 52 the latch member returns 16 to the locking position shown in figure 3 under the influence of the compression spring 17 and the roller 22 engages a locking face 56 on the striking plate 52 and locks the sash 4 with the gasket compressed.

[0028] Opening of the window is performed by an operator manipulating the operating member 18 in the opening direction about the fourth pivot axis against the force of the helical torsion spring 29, whereby the latch member 16 with the roller 22 withdraws from engagement with the locking face 56.

[0029] A resilient tongue 30 on the base member engages a cam 31 on the link member 14 and keeps the snap lock in the opening position shown in figure 4. The helical torsion spring 29 is not strong enough to overcome the engagement between the resilient tongue 30 and the cam 31. However, it is relatively easy for an operator to disengage the resilient tongue 30 by a light pressure on the operating member 18 in the closing direction.

[0030] By having the possibility of keeping the latch member 16 in the opening position is possible to operate the window without the snap lock.

[0031] The movement of the four link mechanism in the opening direction is limited by the link member 14 abutting with a stop cog 33 provided on the base member.

[0032] The roller 22 is not placed directly above the second pivot axis 15, but instead it is placed offset relative to the second pivot axis 15. The offset is in the direction towards the operating member. The offset is by a distance "d" in the direction from the second pivot axis towards the third pivot axis (or as seen in the direction of the longitudinal extend of the base member).

[0033] This distance d is illustrated in the figures as follows.
Figures 6 show a first straight line Y perpendicular to be planar abutment surface 12 of the base member 10, and this first straight line Y intersects with the firth pivot axis of the roller 22. Figure 6 also shows a second straight line YY perpendicular to the planner abutment surface 12 of the base member 10 and this second straight line YY intersects with the second pivot axis. The first straight line Y is displaced relative to the second straight line YY by a substantial distance d in the direction of the operating member. The straight lines Y and YY are parallel with the major component of the force that is exerted on the latch member 16 when an attempt is made to force the window open by an object hitting the window. By placing fifth pivot axis of the roller 22 more towards the operating member 18 the capacity of the snap lock 1 to resist forced opening is significantly improved.

[0034] In an embodiment the fifth pivot axis 20 is placed between the second pivot axis 15 and the first pivot 13 axis when seen in the direction to the longitudinal extend of the base member 10 when the latch member is in its closed position. In an embodiment the fifth pivot axis 20 is also placed between the second pivot axis 15 and the first pivot 13 axis when seen in the direction to the longitudinal extend of the base member 10 when the latch member is in its locked position.

[0035] Figure 8 shows the striking plate assembly 50 in greater detail. The striking plate assembly 50 includes a first plate member 52 that is provided on its front face with a protrusion for forming a locking face 56 and with two substantially parallel protrusions on the front face at form sidewalls 55. The locking face 56 forms together with the sidewalls 55 a recess in the first plate member 52 for receiving the protruding part 21 of the latch member 16 including the roller 21. The sidewalls 55 and the protrusion at least partially conceal the recess and in the locked position of the window or door the roller 22 of the latch member 16 will also at least be partially concealed in the recess. The first plate member 52 of the striking plate assembly is provided with the slot 51 for receiving a screw for mounting the first plate member 52 on a frame part of the window or door, so that the position of the plate member 52 is adjustable. The slot 51 is placed in the center of the recess. The first plate member 52 is also provided with two (slot shaped) apertures 53 for receiving screws or the like for securing the first plate member 52 on a frame part of a window or door. The rear side of the first plate member 52 is provided with parallel serrations 57. The first plate member 52 is configured for mounting on the surface of the frame member of the window. The striking plate assembly 50 also includes a second plate member 60 intended for countersunk mounting in the frame of the window or door. The second plate member 60 is provided with serrations 67 matching the serrations on the rear side of the first plate member 52. The second plate member 60 is also provided with an aperture 61 for receiving the screw that is also received in the slot 51 in the first plate member 52. The serrations 57,67 are relatively fine so as to allow mounting of the first plate member 52 in various positions relative to the second plate member 60.

[0036] The serrations 57,67 are though large enough to provide for a secure connection between the two plate members 52,60 that prohibits any displacement between the two plate members 52,60 relative to one another in the direction perpendicular to the locking face, and in particular in the direction of a force opening the window. Since the second plate member 60 is countersunk it is very difficult for it to be moved by an impact force. The serrations 57,67 make it in turn very difficult for the first plate member 52 to move relative to the countersunk second plate member 60 in a direction perpendicular to be extent of the serrations. Thus, it is very difficult for impact force to move the first plate member 52 relative to be second plate number 60.

[0037] The second plate member has a non-symmetrical outline, so that it can only be mounted in one orientation in a corresponding recess in the window or door frame.

[0038] The term "comprising" as used in the claims does not exclude other elements or steps. The term "a" or "an" as used in the claims does not exclude a plurality.

[0039] Although the present invention has been described in detail for purpose of illustration, it is understood that such detail is solely for that purpose, and variations can be made therein by those skilled in the art without departing from the scope of the invention.

Claims

1. A snap lock assembly for securing an openable aperture closure member in closed position relative to an aperture defined by a frame, said snap lock assembly comprising:

a base member for mounting on the aperture closure member, a link member, a latch member, and an operating member for manipulation by an operator, said link member is connected to the base member by a first hinge with a first pivot axis, said latch member is connected to said link member by a second hinge with a second pivot axis, said operating member is connected to said latch member by a third hinge with a third pivot axis, said base member is connected to said operating member by a fourth hinge with a fourth pivot axis, so that the base member, the link member, the latch member and the operating member form a four-link mechanism, said four link mechanism enables the latch member to move between an extended locking position and a retracted opening position, said latch member is provided with a protruding part for engagement with a striking plate, said protruding part provided with a roller for contact with a locking face of the striking plate, said roller having a fifth pivot axis and said base member has a substantially planar abutment face for abutment with a face of the openable aperture closure member, characterized in that said fifth pivot axis is offset relative to said second pivot axis in the direction of the operating member when the latch member is in its closed position.

2. A snap lock assembly according to claim 1, wherein a straight line perpendicular to said abutment face and intersecting said fifth pivot axis is offset by a substantial distance d in the direction of the operating member from a straight line perpendicular to said abutment face intersecting with the second pivot axis when the latch member is in its closed position.

3. A snap lock assembly according to claim 1, wherein said first pivot axis, said second picot axis, said third pivot axis and said fourth pivot axis are mutually parallel and substantially parallel with said abutment face.

4. A snap lock assembly according to any of claims 1 to 3 wherein said snap lock assembly further comprises a striking plate assembly, and wherein said striking plate assembly comprises a first plate member for mounting on to the frame member and a second plate member for counter sunk mounting in the frame member.

5. A snap lock assembly according to claim 4, wherein said first plate like member and/or said second plate like member are provided with means to prevent in the first plate member to displace relative to the second plate number.

6. A snap lock assembly according to any of the preceding claims, wherein the fifth pivot axis is placed between the second pivot axis and the first pivot axis when seen in the direction to the longitudinal extend of the base member when the latch member is in its closed position.

7. A snap lock assembly according to any of the preceding claims, wherein the fifth pivot axis is placed between the second pivot axis and the first pivot axis when seen in the direction to the longitudinal extend of the base member when the latch member is in its closed position and when the latch member is in its locked position.

8. A striking plate assembly for engaging a latch member of a snap lock, said striking plate assembly comprises a first plate like member for mounting on a surface of the object to which the striking plate assembly is to be attached and a second plate like member for countersunk mounting in the surface of the object to which the striking plate assemblies to be attached, said first plate like member is provided with a projection on its front face that creates a locking face and two parallel projections on its front face that create sidewalls that in combination with the locking face define a recess in the front face of the first plate like member for receiving portion of the latch member, a slot for receiving a screw or the like but therethrough is formed in said recess and a portion of the rear side of the first plate like member is provided with serrations or the like, and said second plate like member is provided corresponding serrations or the like on its side that faces the first plate like member.

9. A striking plate assembly according to claim 6, wherein said serrations or the like are substantially parallel to the locking face.

10. A striking plate assembly according to claim 6 or 7, wherein the outline of said second plate member is asymmetrical.

Drawing